Device for transporting loads under water and usable as a lifting pontoon

ABSTRACT

A device for the transport of loads under water which may be used also as a loading bridge, allows to reach great depths under water and comprises a tank (S), two tanks (Sg) and a float (G) in which the pressure automatically remains equal to the external hydrostatic one, due to a valve (V) with four functions that assures the air volume, predetermined in the loading phase, to be constant inside the tank with the variation of the depth.

CROSS REFERENCE TO RELATED APPLICATION

This is the 35 USC 371 national stage of international applicationPCT/IT00/00408 filed Oct. 13, 2000, which designated the United Statesof America.

FIELD OF THE INVENTION

The present invention concerns a device for the transport of loads underwater and that may be used also as a loading bridge.

BACKGROUND OF THE INVENTION

The great difficulties are well known that are met when refloating sunkfinds and the remains of incidents or wrecks by means of big balloons orinflatable structures that are coupled to the objects on the ground ofthe sea for lifting them up, even when they are very heavy. In fact, itoften happens that those structures come off the string, loose air andit is rather difficult to manage them when the sea is rough or stormy.

SUMMARY OF THE INVENTION

It is the aim of the present invention to realize a means completelydifferent from all existing means in this field, for the transport ofloads under water and that may also be used as a loading bridge.

The aim set forth is reached by means of the device according to thepresent invention that allows to reach great depths under water withoutcomplicated structures, in which the pressure of the tanks and of afloat, forming said device, automatically remains equal to the externalhydrostatic one, due to a valve with four functions that assures the airvolume predetermined in the loading phase to be constant inside the tankwith the variation of the depth.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described more in detail hereinbelowrelating to the enclosed drawings in which an embodiment is shown.

FIG. 1 shows a lateral scheme of a device for the transport of loadsunder water and that may be used also as a loading bridge, according tothe present invention.

FIG. 2 shows a safety system of the device according to the presentinvention, as shown in FIG. 1.

FIG. 3 shows in particular the loading bridge.

DETAILED DESCRIPTION OF THE INVENTION

The enclosed figures show a device for the transport of loads underwater and that may be used also as a loading bridge, in which thepressure in a tank S, in tanks Sg and in the float G alwaysautomatically remains equal to the hydrostatic external pressure, due toa valve V that assures the air volume, predetermined in the loadingphase, to remain constant inside the tank with the variation of thedepth, said valve having the following four functions:

a metric rod 3 determines the air volume Var requested for keeping theload P to be transported in a floating condition; if, e.g., Var=1 cubicmeter, the device receives a push upwards of 1,000 kg, coupling a load Pequal to 1,000 kg and sinks to the free surface of the water, as it isprovided with two floating tanks Sg which have an air volume equal tothe weight of the whole structure;

opening of the valve 2 e for the air inlet into tank S, into tanks Sgand into the float G for keeping constant the air volume and thepressure and thus obtaining the stable floating of the device; reducingthe air volume the device receives a push downwards and the water enterspipes 10, and the pressure increases while the device goes down; insidetank S the water level increases so that the float operates valve 2 euntil the internal pressure is equal to the external one andconsequently the Var is equal to the predetermined one. The compressedair is supplied by a bottle 1 loaded at least at 200 atm, and betweenthe bottle and the valve a pressure reducer is inserted, set at least at30% more than the depth to be reached;

opening of the valve 2 u for the outlet of the air from tank S, which isnecessary for allowing the inlet of water through pipes 10 and formaking the device come down; said valve 2 u may also be controlled by anemergency device 6 that intervenes in case of a sudden loss of thetransported load;

acceleration and/or braking of the device according to the presentinvention in its vertical movements, by means of a system 4 ofgear-wheels and hand grip C which adjust the position of metric rod 3and of float G with respect to the oscillating cylinder 5 which, withtwo adjustable teeth, opens valves 2 e and 2 u so that, by means ofsmall rotations of hand grip 4, those small air quantities are let inand/or ejected from tank S for lightening or making heavier the deviceaccording to the present invention so as to go up or down, while thespring stabilizing pallet N with a screw for adjusting the pressure ofcylinder 5, prevents sudden oscillations of valve V when the deviceperforms vertical movements. When the device moves downwards due to theexternal pressure, the water volume increases, float G rises and valve 2e opens until the predetermined balance of the water level inside tank Sis restored; furthermore, as the inlet time of air and water aredifferent, the diameter of pipes 10 is calibrated onto the air speed—forthe inlet and for the outlet—, while cylinder 5 has a plurality ofgrooves so as to be an obstacle to the sliding of pallet N, theadjusting system whereof is fixed at the base. The crank 7 allows themanual opening of the air.

For what concerns the safety system: in case of accidental unhooking ofthe transported load, the device receives a sudden upward push and, evenif valve V intervenes, the Var remains constant with the consequent needof quickly flooding tank S, which may be obtained as follows: pulley 8has a winding spring inside, and rotates around the axis of the centraltraverse of frame T; when it is in position a, it means that the weighthas been loaded; when the load gets accidentally unhooked, the returnspring brings the pulley in position b, the tooth c moves the leversystem 6 that lowers cylinder 5 and, by means of a lower tooth, keepsvalve 2 u open: air gets out and water in through pipes 10; if the waterinlet through pipes 10 is too slow with respect to the need of stoppingthe rise of the device according to the present invention in a fewmeters, an additional quick flooding valve 13 will be operated, placedin the upper part of tank S and shaped for having a great carriage andthat will be opened by the depression determined in the tank and by thepressure performed by the water column.

In normal conditions, said valve 13 will be kept closed by the internalpressure and by two small arched steel blades, opportunely calibrated;it has its central pin in the cap and the ends thereof are resting onthe edge of the hole in tank S.

Following the flooding of tank S, the device according to the presentinvention will become heavier but tanks Sg will remain filled with airand will keep it in a stable floating position making it slowly emerge.

If the load to be transported is connected to an emergency rope D, itwill be possible to find it. The emergency rope has two functions: itacts as a fishing-line and it slows down the descent of the load and therising of the device according to the present invention.

The cover 9 blocks wheel 8 in position a in two cases: during loadingand when the load is transported onto the upper part of the frame. Thesafety system works with return spring Mn.

The present invention also provides for a pressurization of the devicethat may touch great depths because the internal pressure of tank S isalways equal to the outer pressure due to valve V, while float G andtanks Sg must be connected with compressed air from compressed airsource 1 behind the outlet of valve 2 e so that said tanks and saidfloat will always be filled with air and with a pressure equal to theone of tank S.

For obtaining an optimal working of the device according to the presentinvention, the diameter of pipes 10 must be well dimensioned to the oneof valves 2 e and 2 u for obtaining the movement speed and theintervention time of the emergency system. During the daily use of thedevice, also adjusting taps at the inlet of pipes 10 may be useful.

For what concerns the loading system of the device for transportingloads under water, it is necessary to well balance the air volume andthe water volume for obtaining the maximum safety in the loading phase.

For this purpose, it is convenient to combine the loading and/orunloading bridge shown in FIGS. 2 and 3 to the device according to thepresent invention: the frame T has resting rods Ba, which may beadjusted in height and the position whereof depends on the weight of theload and on the position of loading and/or unloading of the device.

In the mentioned cases, the device according to the present inventionchanges its position with respect to the loading bridge.

The loading bridge Tc may be laterally coupled to a mole or to a boat.

For making the displacement easier, the device according to the presentinvention may be provided with propellers and rudders R.

What is claimed is:
 1. A device for changing a depth of an object,comprising: a connection (8) for an object whose depth is to be changed;a supply (1) of compressed air; a first tank (Sg) having an air volumecorresponding to a weight of the device; a second tank (S) connected tosaid first tank and filled with air and water, said second tank having afirst opening (10) for passage of water to and from outside said secondtank; a float (G) that floats on water in said second tank; and a valveassembly (V) on said second tank, said valve assembly including, a firstvalve (2 e) that selectively connects said supply of compressed air tosaid second tank, a second valve (2 u) that selectively releases airfrom said second tank, a first movable member (5) having a firstprojection for operating said first valve and a second projection foroperating said second valve, and a second movable member (3) connectedto said float and whose position relative to said first movable memberis adjustable from outside the device, wherein movement of said firstmovable member in a first direction operates said first valve toincrease a buoyancy of the device and movement of said first movablemember in a direction opposite the first direction operates said secondvalve to decrease the buoyancy of the device.
 2. The device of claim 1,wherein said first movable member is a cylinder and said second movablemember is a rod that moves within said cylinder, and further comprisinga gear assembly (4) for moving said rod from outside the device.
 3. Thedevice of claim 1, further comprising a damper (N) for dampingoscillations of said first movable member.
 4. The device of claim 1,wherein said connection comprises a rotatable member that is urged in afirst direction when said connection is not connected to an object, andfurther comprising a lever assembly (6) that is displaced by movement ofsaid rotatable member in the first direction and that is operablyconnected to said second valve to operate said second valve to decreasethe buoyancy of the device when said rotatable member moves in the firstdirection.
 5. The device of claim 4, wherein said rotatable member is apulley.